Faucet stem removal

Hello. I have a faucet with a very difficult to turn handle. I figured how to remove the handle (set screw), but can't figure out how to remove the escutcheon to get to the stem. I tried unscrewing and pulling straight up. It doesn't seem to budge. The lower ring does seem to be a separate piece. Has anyone seen one like this? Probably from the late 80s.

Thanks, HJ. Do you think there is a flat portion of the body (currently between the top and bottom surfaces of the counter) that I can use to hold back on when removing the upper portion? When I had the body retaining nut on and tried to remove the upper portion, the whole thing wanted to twist.

Short update on this--I got it fixed by removing the valve and using the upper and lower body retaining nuts as a double nut lock so I could hold back on the threaded body without mangling the threads. After I struggled to reconnect the flexible line to the spout (the vinyl line was difficult to tighten with very limited access), I realized that I could have saved a bunch of time by removing the upper retaining nut from the hot side and using that together with the upper retaining nut on the cold side to remove the cartridge without doing anything under the counter. D'oh!

By the way, HJ, it does look very similar to the Santec design. I called their tech support. A man told me their valves have flats on the bottom of the threaded portion near the supply lines so this must be a different maker or an old model.